[en] Dy adatom adsorption and penetration on defected graphene were studied using first-principles calculations. We show that adsorption of Dy adatom on defect is energetically more favorable than on pristine graphene. Strong covalent bonding between Dy and C atoms at the defect sites is confirmed by interaction charge density analysis. We also found that the pathways for Dy penetration through defects with 1 and 2 missing carbon atoms are different from those through larger holes in graphene due to strong spatial confinement effects. The larger size of the hole is, the smaller barrier for Dy penetration. (paper)

[en] Published in summary form only

[en] In this work, the mean excitation energies of atoms from Z = 1 to 54 were calculated. The calculations were carried out by using three different atomic electron densities. Thomas–Fermi electron densities with two different screening functions and Roothan–Hartree–Fock (RHF) electron densities were used. Obtained results show the RHF electron densities give more accurate results than others. In mean excitation calculations, γ is set to $\sqrt{2}$ as suggested. However, when mean excitation energies are normalized to the reference values, it is found that γ values are ranging from 0.8 to 1.8. By using these γ values, one can be calculated the effective mean excitation energy more accurately than previous calculations.

[en] Self-consistent theory for concentrated electrolytes is developed. Oscillatory decay of the charge–charge correlation function with the decay length that shows perfect agreement with the experimentally discovered and so far unexplained scaling is obtained. For the density–density correlations, monotonic asymptotic decay with the decay length comparable with the decay length of the charge correlations is found. We show that the correlation lengths in concentrated electrolytes depend crucially on the local variance of the charge density. (letter)

[en] The superfluid density or superconducting (SC) carrier concentration n _sc of cuprates has been the subject of intense investigations but there is not any single theory capable to explain all the available data. Here we show that the behavior of n _sc in under and overdoped cuprates are a consequence of an SC interaction based on charge fluctuations in the incommensurate charge-density-waves (CDW) domains. We have shown that this interaction scales with the CDW amplitude or the pseudogap (PG) energy, yielding local SC amplitudes and Josephson currents. The average Josephson energy $⟨E_{\mathrm{J}}⟩$ is proportional to the phase stiffness or superfluid density ρ _sc ∝ n _sc. We find that n _sc(p) increases almost linearly with doping p in the underdoped region and in the charge abundant overdoped only a few fractions of the holes condense leading to two kinds of carriers, a recently confirmed feature. The calculations and the ρ _sc data uncover how the PG–CDW–SC intertwined orders operate to yield cuprates properties. (paper)

[en] Highlights: • Ehrenfest Force F(r) applied to the two C-O ring-opening photo-reactions of oxirane. • Ehrenfest Force trajectories and hybrid stress tensor trajectory calculated with the F(r) BCPs. • Torsion of the CH₂ group facilitated the photo-reaction pathway towards the CI. • Torsion of CH₂ group induced symmetry breaking evident from S₀ and S₁ F(r) trajectories. • Agreement found between the Ehrenfest Force and hybrid stress tensor trajectories. Ehrenfest Force F(r) trajectories were constructed for the C-O ring-opening photo-reactions of oxirane. The F(r) trajectories were constructed in an eigenvector-space corresponding to bond-flexing, bond-twist and bond-anharmonicity associated with the least and most preferred directions of charge density accumulation and bond critical point (BCP) sliding respectively. The presence of the torsion of a CH₂ group for one of the photo-reactions led to greater symmetry breaking and greater reaction pathway preference. Consistency was found from hybrid Ehrenfest Force F(r) trajectories that were constructed using the Ehrenfest Force F(r) BCPs and the stress tensor eigenvectors.

[en] The coupling of phonons with collective modes and single-particle gap excitations associated with one (1d) and two-directional (2d) electronically-driven charge-density wave (CDW) ordering in metallic RTe₃ is investigated as a function of rare-earth ion chemical pressure (R = Tb, Dy, Ho) using femtosecond pump-probe spectroscopy. From the T-dependence of the CDW gap Δ_CDW and the amplitude mode (AM) we find that while the transition to a 1d-CDW ordered state at Tc1 initially proceeds in an exemplary mean-field (MF)-like fashion, below T_c1, Δ_CDW is depressed and departs from the MF behavior. The effect is apparently triggered by resonant mode-mixing of the amplitude mode (AM) with a totally symmetric phonon at 1.75 THz. At low temperatures, when the state evolves into a 2d-CDW ordered state at T_c2 in the DyTe₃ and HoTe₃, additional much weaker mode mixing is evident but no soft mode is observed.

No abstract available

[en] Highlights: • A piezoelectrochemical reaction is theoretically investigated. • The reaction takes place within a molecular compression chamber (MCC). • Molecular hydrogen is formed in situ and stored inside the MCC cage. • Besides H₂ the MCC cage can also host F₂ or a monoatomic gas. Nitrogen-containing molecular compression chambers (MCCs) undergo stepwise protonation followed by a 2-electron reduction step which affords molecular hydrogen in situ. This piezoelectrochemical reaction is favored by the high compression that characterizes the molecular skeleton of MCC and its fluorinated analogue. Besides H₂, the MCCs are also capable of trapping molecular fluorine and the small monoatomic gases helium and neon. A topological analysis of the electronic charge density reveals the presence of closed-shell interactions between hosts and guests.

[en] An axion insulator is a correlated topological phase, predicted to arise from the formation of a charge density wave in Weyl semimetals. The accompanying sliding mode in the charge density wave phase, the phason, is an axion. It is expected to cause anomalous magneto-electric transport effects. However, this axionic charge density wave has so far eluded experimental detection. In this paper, we report for the first time the observation of a large, positive contribution to the magneto-conductance in the sliding mode of the charge density wave Weyl semimetal (TaSe${}_4$)${}_2$I for collinear electric and magnetic fields (EB). The positive contribution to the magneto-conductance originates from the anomalous axionic contribution of the chiral anomaly to the phason current, and is locked to the parallel alignment of E and B. By rotating B, we show that the angular dependence of the magneto-conductance is consistent with the anomalous transport of an axionic charge density wave.